Truck body with bottom conveyor assembly

ABSTRACT

A truck body having pallet supporting rollers incorporated into the bottom thereof combined with a loading apparatus for receiving loaded pallets in the rear of the truck body and automatically moving them sequentially forward until the body is fully loaded, together with an unloading apparatus for automatically and sequentially moving loaded pallets to the rear of the truck body with a manually operated mechanism being provided for shifting the mechanism from a loading mode to an unloading mode.

Mickey et a1.

[ 1 Oct. 23, 1973 [54] TRUCK BODY WITH BOTTOM CONVEYOR 3,529,481 9/1970Budzyn 214/516 X ASSEMBLY 3,346,132 10/1967 Duszka 214/56 3,250,4085/1966 Daniluk et a1. 214/8322 X [75] Inventors: Carl F. Mickey;Lawrence E.

Mlckey both of High Pomt Primary Examiner-Albert J Makay [73] Assignee:W. F. Mickey Body Company, Inc., Attorney-Harvey B. Jacobson High Point,N.C.

[22] Filed: Dec. 14, 1971 57 ABSTRACT PP No.1 ,769 A truck body havingpallet supporting rollers incorporated into the bottom thereof combinedwith a loading 52 US. Cl. 2l4/83.22, 214/833 apparatus receiving made?Pane the 51 Int. Cl 860p 1/36 the truck and aummatcally 58 Field 61Search 214/516 83.22 83.24 quemiany fmwa'd is fully waded 214/518 832682 gether with an unloading apparatus for automatically 6 andsequentially moving loaded pallets to the rear of [56] References Citedthe truck body with a manually operated mechanism being provided forshifting the mechanism from a UNITED STATES PATENTS loading mode to anunloading mode. 3,572,563 3/1971 Oliver 214/516 3,522,919 8/1970 Bader214/516 X 9 Claims, 12 Drawing Figures -1- 24) l l /]1 I in inPAIENIEllocraama 3.751.067

SHEET 10F 4 Carl F: Mickey Lawrence E. Mickey INVESTORS 9 @4 a515 .Us L:J g R PAIENIEnum 23 m5 SHEET R [If 4 Car/ F. Mic/ e Lawrence EM/ckey 1x1'IENI'OKS TRUCK BODY WITH BOTTOM CONVEYOR ASSEMBLY BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention generallyrelates to truck bodies and more particularly truck bodies constructedespecially for transporting palletized loads, such as beverages, or thelike, with the bottom of the truck body incorporating a conveyorassembly with a loading mechanism and unloading mechanism incorporatedtherein to move pallets longitudinally of the truck body during theloading and unloading operation.

2. Description of the Prior Art Truck bodies have been provided withmany structures to facilitate the loading and unloading of articles ormaterials. In the beverage industry, the present practice involved isthe loading of bottled or canned beverages onto pallets with the palletsbeing loaded onto a truck body for transport to a destination where thepallets are unloaded from the truck body. To facilitate the loading andunloading of the palletized beverages, low friction conveyors, such asrollers, or the like, have been incorporated into the bottom of thetruck body. However, while such devices perform their function,substantial difficulties have been encountered in mov ing the palletizedloads longitudinally of the truck body and maintaining the palletizedloads stationarily within the truck body during over-the-road movement.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a truck body with a conveyor assembly in the bottom thereofcombined with a loading assembly and an unloading assembly driven in amanner to enable pallets placed into the truck body at one end thereofto be conveyed forwardly during the loading operation and move thepallets rearwardly during the unloading operation.

Another object of the invention is to provide a truck body incorporatinga loading and unloading device and including a manually shifting meansfor selectively conditioning the mechanism for operating in a loadingsequence or an unloading sequence.

A further object of the invention is to provide a truck body inaccordance with the preceding objects in which the loading and unloadingmechanism includes a travelling bulkhead positioned at all times infront of the load, together with a load bar assembly at the rear of thetruck body which is moved longitudinally of the truck body to move aloaded pallet into the truck body a distance sufficient to receiveanother pallet when the load bar mechanism returns to its rearmostposition.

Still another object of the invention is to provide a truck body havinga loading and unloading mechanism associated therewith adapted to beincorporated into a van-type trailer, such as those employed totransport two longitudinal rows of palletized beverage containers toenable the loaded pallets to be loaded onto the truck body and unloadedfrom the truck body at the rear end thereof, thereby eliminating thenecessity of gaining access to the truck body along the complete lengthof each side thereof which is necessary when loading conventionaltrailers or truck bodies of this type which have roll-up doors alongeach side of the body.

Yet another important feature of the invention is to provide a truckbody with a loading and unloading apparatus in accordance with thepreceding objects which is relatively simple in construction, dependableand long lasting, adapted to be installed in various types of truckbodies, and relatively inexpensive to manufacture, operate and maintain.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing bad to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a truck bodywith the loading and unloading apparatus of the present invention incorporated therein;

FIG. 2 is a longitudinal, sectional view taken substantially upon aplane passing along section line 2-2 of FIG. 1 illustrating thestructural details of the invention;

FIG. 3 is a detailed sectional view illustrating a portion of the drivemechanism for the loading and unloading apparatus;

FIG. 4 is a detailed sectional view taken substantially upon a planepassing along section line 4-4 of FIG. 1 illustrating the structure ofthe travelling bulkhead at the forward end of the load in the truckbody;

FIG. 5 is a transverse, sectional view taken substantially upon a planepassing along section line 5-5 of FIG. 1 illustrating the relationshipof the structural components of the invention;

FIG. 6 is a fragmental plan view illustrating the manually shiftableclutch mechanism for the loading and unloading mechanism;

FIG. 7 is an elevational view observing the shifting mechanism from theforward end thereof;

FIG. 8 is a sectional view taken substantially upon a plane passingalong section line 8-8 of FIG. 7 illustrating shifting fork and-relatedmechanism;

FIG. 9 is an exploded perspective schematc view of the loading andunloading mechanism;

FIG. 10 is a schematic wiring diagram illustrating the electricalcircuitry for operating the loading and unloading apparatus;

FIG. 11 is a detailed sectional view illustrating the longitudinal railand tubular runner construction mounted thereon; and

FIG. 12 is a fragmental plan view, on a reduced scale, illustratingschematically the manner in which pallets may be loaded from the rearside comer of the truck body.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now specifically tothe drawings, the truck body of the present invention is generallydesignated by the reference numeral 20 and is of conventionalconstruction insofar as the shell, running gear, suspension assembly andrelated structural components are concerned, with the truck bodyincluding a bottom panel or base 22, and upstanding side walls 24separated into two compartments or longitudinal spaces 26 and 28 by alongitudinal partition 30. The length and width dimensions of the bodyand the spaces may vary depending upon local regulations and individualrequirements.

The front of the truck body 20 is provided with a front wall 32 and therear thereof may be provided with a suitable closure door or closuredoors, the details of which are not shown. Inasmuch as the structure oneach side of the partition is identical insofar as the loading andunloading mechanism is concerned, only one loading and unloadingmechanism will be de scribed in detail with it being understood thatboth compartments or spaces 26 and 28 are likewise equipped. The loadingand unloading apparatus is adapted to load and unload palletized loads34 in which the pallets on which the articles are placed are ofconventional construction and are handled by suitable load handlingequipment, such as a fork truck or the like.

Disposed adjacent each side edge of the compartment 26 is a plurality ofrollers 36 which are disposed in staggered relation, as illustrated inFIG. 1, with each roller 36 being journaled by a suitable supportingaxle 38 supported by longitudinal support rails 40 supported from thebase or bottom panel 22 by supporting brackets 42. Similar staggeredsupporting rollers 44 are provided centrally of the space 26 and aresupported by similar axles 46 supported by rail 48 and supported bybrackets 50 with the aligned rollers 44 being spaced apart further thanthe rollers 36 and receiving an elongated endless chain 52 therebetween,as illustrated in FIG. 5, with the upper run of the chain being disposedslightly below the top peripheral surfaces of the rollers 44. The lowerrun of the chain 52 is disposed below the rollers and between thebrackets 50. The forward end of the chain 52 which is in the form of asprocket chain is entrained around a forward sprocket gear 54 while therear end of the sprocket chain 52 is entrained around a sprocket gear56. The forward sprocket gear is connected to a supporting axle 58supported by suitable brackets 60 while the rear sprocket gear 56 isjournaled on a drive shaft 62 supported by suitable brackets or bearingblocks 64.

With this construction, the rollers 36 and 44 form a low frictionconveyor surface for movably supporting the pallets 34 for longitudinalmovement in the space 26 with the pallets having one dimension generallyequal to the width of the space or compartment 26 with some space beingprovided between the side walls 24 and the partition 30 to enable anoperator of a fork lift truck to readily position loaded pallets intothe rear of the space 26 and remove loaded pallets therefrom.

Supported from the inner rails 40 which are L-shaped in configuration isa travelling forward bulkhead or wall 66 which has a pair of rearwardlyextending members 68 on the bottom edge thereof supporting a pair ofrollers 70 which are rollingly engaged with the horizontal flanges onthe innermost rails 40, as illustrated in FIG. 5. The bulkhead 66 isattached to the sprocket chain 52 for movement therewith as indicated at72 with this connection being a suitable detachable connection which maybe in the form of a bolt-type fastener or a depending pin arrangementwhich may be detachably engaged with the sprocket chain 52 which may bein the form of a conventional roller chain or the like. The rollers 70which support the longitudinal members 68 which in turn support thebulkhead 66 may be in the form of spherical rollers which have thebottom peripheral surface engaging the horizontal flange of each innerrail 40 and the inner surface thereof engaging the vertical flange ofthe inner rail 40 for guiding reciprocatory movement of the travellingbulkhead 66 in relation to the truck body for unloading the pallets 34in a manner described hereinafter.

The rear of the space 26 is provided with a loading mechanism generallydesignated by numeral 74 which includes a transversely extending loadingbar 76 attached to a pair of forwardly extending tubular supportingmembers 73 that are longitudinally slidably mounted on a pair ofhorizontally extending guide rails 80 supported from the base bydownwardly diverging brackets 82, as illustrated in FIG. 12. The forwardends of the tubular support members 78 are connected to one end of asprocket roller chain 84 which extends along the top surface of theguide rail 80 and is entrained over a sprocket gear 86 fixed to a shaft88 journaled in bearing blocks 90 with the chain 84 then extendingrearwardly along the floor surface 22 and around an idler sprocket gear92 journaled by a shaft 94 supported by brackets 96 with the terminalend of the chain then extending forwardly and being connected to thedepending projection 98 on the forward bottom end of the tubularsupports 78. As illustrated, two tubular supports 78 are provided witheach of them being identical in construction and associated with a chain84 in the same manner. The chains 84 are driven by a sprocket gear 100rigid with the shaft 88 with the sprocket gear 100 being driven by asprocket chain 102 entrained over a sprocket gear 104 journaled on'theshaft 62. Thus, as the chains 84 are driven in reverse directions, theloading bar 76 along with the tubular supporting members 78 will bereciprocated longitudi nally of the guide rails 80 a distance to move apallet 34 placed inwardly of the loading bar 76 a distance forwardly toenable another pallet to be placed inwardly of the loading bar when theloading bar has returned to its rearmost position, thereby moving thepallets forwardly in increments approximately equal to the length of thepallet with the pallets being abutted against each other as the loadingbar moves forwardly thus causing all of the pallets in the truck body tomove forwardly and the bulkhead also to move forwardly until the space26 is completely loaded. I

To drive the shaft 62, a reversible gear head type motor 106 is providedwith an output sprocket gear 108 driving a sprocket chain 110 extendingupwardly and entrained over a sprocket gear 112 affixed to the shaft 62.

For selectively driving the chain 52 for moving the travelling bulkhead66 or the chain 102 for moving the load bar 76 and supports 78, anaxially shiftable'clutch member 114 is splined or keyed to the shaft 62for reciprocation thereon. Each end of the clutch member 114 is providedwith teeth 116 for engagement with corresponding teeth 118 on thesprocket gear 104.0r teeth 120 on the sprocket gear 56 so that in oneshifted position of the clutch 114, power from the shaft 62 will betransmitted to the clutch member 114 to the sprocket gear 56 and in theother position of the clutch 114, power will be transmitted to thesprocket gear 104. Any suitable type of clutch mechanism or clutch facesmay be employed as long as a positive driving connection is providedselectively between the clutch 114 and the respective sprocket gears 56and 104.

The periphery of the clutch member 114 is provided with a groove 122receiving the bifurcated end of a shifting fork 124 that is moved in adirection parallel to the shaft 62 for shifting the clutch member 114.The

fork 124 is attached to a bar 126 that is substantially perpendicular tothe fork and parallel to the shaft 62. The bar E26 is longitudinallyslidably supported in bracket members 128 supported from an L-shapedbracket 130. The ends of the bar 126 are provided with inturned lugs 132received on a rod 134, which have transverse retaining pins 136 at eachend thereof and which receives a shifting spring 138 thereon which has aspring loading shifting bar 140 and is connected centrally thereto sothat when the shifting bar 140 is longitudinally reciprocated, thespring 138 will be compressed between the bar 140 and the opposed lug132 thereby exerting spring pressure on the slide member 126 for biasingthe clutch yoke 124 thereby shifting the position of the clutch 114,This construction enables spring pressure to be exerted on the clutchmember 1 14 so that the teeth thereon can become aligned properly withthe teeth on its mating sprocket gear.

The spring loading shifting bar 140 is attached pivotally to one end ofan eccentric arm 142 rigid with a shaft 144 which extends through thevertical mounting plate 130 and includes a slot 145 in the end thereoffor receiving the blade end of a T-shaped operating handle 146 on theouter end thereof so that when the shaft 144 is pivoted, the eccentricarm 142 will cause longitudinal shifting movement of the point ofconnection between the shifting bar l40and the spring 138. Suitableindicia may be provided in association with the slotted end of the shaft144 and the adjacent frame structure to indicate whether the mechanismis in the load or unload phase. The handle 146 could be welded orotherwise fixed to the end of shaft 144 but the separate handle preventsthe operator from shifting the mechanism from one phase to another whilethe unit is in operation. Also, mounted on the vertical plate 130 is alimit switch 148 having a limit switch arm 150 in the path of movementof a projection 152 on the shifting bar 140.

With this construction, the drive motor 106 will selectively drive theforward wall or bulkhead or the load bar 76 depending upon the manuallyshifted position of the operating handle 146. .Thus, the loading bar 76may be employed to move a pallet 34 inwardly on the supporting rollers adistance sufficient to enable placement of another pallet onto therollers when the loading bar has been returned to its rearmost position.To move the pallets rearwardly from the front of the truck body, thetravelling bulkhead is moved rearwardly as the pallets are removed fromin front of the loading bar 76 which limits rearward movement of thepallets. In some instances, it may be desirable to unload the palletsonto another conveyor aligned with the supporting rollers in whichevent, the loading bar may be pivoted downwardly to the dotted lineposition illustrated in FIG. 2, which is accomplished by the loading bar76 having depending brackets 77 attached pivotally to the lower bottomcorners of the tubular support 78 by a pivot pin or bolt 79 and aremovable fastener 81 extending through matching apertures in thetubular support 78 and the bracket 77 thereby enabling the loading bar76 to be pivoted downwardly so that pallets 34 may be loaded onto or offof the supporting rollers when the supporting rollers are aligned withanother conveying apparatus or loading apparatus which is capable ofmoving the pallets onto the truck body or removing pallets therefrom.

The loading and unloading operation of the loading bar and travellingbulkhead, respectively, are automatic and controlled by switchespositioned for actuation and response to presence of, absence of orposition of the pallets, and while the specific electrical circuitryitself does not form a significant part of the invention, the automaticoperation thereof is significant and, accordingly, a description of theschematic circuit illustrated in FIG. 10 insofar as operation during theload sequence and unload sequence is included.

In the load sequence, the handle 146 of the clutch is shifted to theload position which mechanically engages the clutch 114 with thesprocket gear 104 and at the same time positions limit switch 148,designated L-l in FIG. 10, which is shown in the unload position.

A push button jog switch J-l will automatically position load bar instart position for loading. Switch L-2 is pallet on start load cycle;switch L-3 is stop reverse load slide start forward load slide; switchL4 is stop forward load slide start reverse load slide; switch L-S isunload limit; switch L-6 is extreme load limit; switch L-7 is extremeunload limit. The timer T-l gives motor time to stop before reversingand timer T-2 permits unload travel to continue to a point 5 inchesoutside rear of trailer from cut-off limit L-5 inside trailer.

FIG. 12 is a small plan view illustrating an embodiment of the inventionin which the pallets are inserted and removed from an opening 200 in theside wall 202 of a truck body generally designated by the numeral 204which has a solid rear end wall 206. In this construction, the opening200 is illustrated as being provided with pivotal closure doors 208 withit being pointed out that any type of closure door or closure device maybe employed for the opening. Operation of the device is the same as thatdescribed previously in which the pallets are loaded and unloaded by theload bar 76 and the travelling bulkhead (not shown in FIG. 12). Thepartition wall may be provided with an adjustment feature so theeffective thickness thereof may be varied to enable pallets of differentwidths to be received in the load receiving spaces so that the palletsare incapable of lateral shifting during over-the-road movement of thetruck body. Also, while the device has been illustrated in combinationwith a truck body, it may also be employed in any suitable type of loadcarrying body receiving various types of loads mounted on pallets orequivalent load carrying platforms.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

What is claimed is:

1. In an elongated load carrying body having a low friction conveyormeans in the bottom thereof for supporting a plurality of load units forlongitudinal movement in relation to the body, a loading and unloadingassembly associated with said body for moving the load unitlongitudinally thereof while supported by the conveyor means, saidloading and unloading assembly comprising a longitudinally travellingbulkhead supported from said body, a longitudinally travelling load abar at one end of the body and supported therefrom for the conveyormeans inwardly of the load bar for movement into the load body during aloading operation,

drive means fixedly connected with the bulkhead for moving the bulkheadlongitudinally toward the loading bar when actuated for unloading loadunits, a single power means for driving the bulkhead and load bar, andmanually operated means selectively connecting the drive means for theload bar and bulkhead to the power means for operating the assembly in aloading mode or unloading mode, said manually operated means preventingsimultaneous actuation of the load bar and bulkhead.

2. The structure as defined in claim 1 wherein said loading bar includesa pair of support members extending longitudinally of the body, a pairof rigid guide rails engaging and supporting said support members forsupporting and guiding the load bar during longitudinal reciprocation.

3. The structure as defined in claim 1 wherein said bulkhead includes avertically upstanding and transversely extending member, supportingroller means carried by said bulkhead for engaging the body androllingly supporting the bulkhead in relation thereto.

4. The structure as defined in claim 1 wherein said means drivingthebulkhead includes an elongated chain supported from the body andincluding an elongated upper run disposed under the bulkhead and beingfixedly attached thereto whereby movement of the chain in eitherdirection will cause longitudinal movement of the bulkhead.

5. The structure as defined in claim 1 wherein said means forselectively controlling driving actuation of the bulkhead and load barincluding a manually shiftable clutch mechanism for selective engagementwith the drive connection with the load bar and bulkhead, reversiblemotor means drivingly connected with the clutch for selectively drivingthe load bar and bulkhead.

6. The structure as defined in claim 1 wherein said load body is in theform of a van trailer having two longitudinalcompartments thereinseparated by a partition with each compartment having a conveyor meansand a loading and unloading assembly therein, said load units being inthe form of palletized beverage containers to, enable loading andunloading of the body from one end thereof thereby eliminating thenecessity of obtaining access throughout the opposed side walls of thebody. 1

7. The structure as defined in claim 6 wherein said conveyor means is inthe form of a plurality of longitudinal rows of rotatably rollerssupporting the load units at transversely spaced points, said rollersbeing freely rotatable for enabling movement of the load units thereonwhen forces are exerted on the load units.

8. The structure as defined in claim 7 wherein said loading bar includesa pair of support members extending longitudinally of the body, a pairof rigid guide rails engaging and supporting said support members forsupporting and guiding the load bar during longitudinal reciprocation,said bulkhead including a vertically upstanding and transverselyextending member, supporting roller means carried by said bulkhead forengaging the body and rollingly supporting the bulkhead in relationthereto, said means driving the bulkhead including an elongated chainsupported from the body and including an elongated upper run disposedunder the bulkhead and being fixedly attached thereto whereby movementof the chain in either direction will cause longitudinal movement of thebulkhead, said means driving the bulkhead being rendered inoperativewhen the load bar is being reciprocated.

9. A load unit handling device in combination with a load body of avehicle in which the body includes .a lowfriction, roller equipped bedcontinuously supporting the load units, an elongated drive membersupported in close proximity to said bed and being movable along areversible, predetermined path along said bed, said path terminatingadjacent forward and rearward extremities of the bed, an unloadingmember connected to said elongated drive member for movementcontinuously therewith, a shorter drive member supported in closeproximity to said bed and being movable along a reversible,predetermined path along said bed, said path of the shorter drive memberterminating at one end at the rearward end of the bed rearwardly of thepath of the elongated drive member and at the other end adistanceforwardly of the rearward end of the bed substantially equal to thefore-to-aft dimension of a load unit, a loading unit disposed above thebed and connected with said shorter drive member for movementcontinuously therewith, a singlereversible power means supportedadjacent the bed, and means connecting the power means to said drivemembers, said connecting means including a shiftable means to actuateonly one of said drive members at a time for loading and unloading aplurality of load units from the rearward end of the bed.

l 1 1! i t

1. In an elongated load carrying body having a low friction conveyormeans in the bottom thereof for supporting a plurality of load units forlongitudinal movement in relation to the body, a loading and unloadingassembly associated with said body for moving the load unitlongitudinally thereof while supported by the conveyor means, saidloading and unloading assembly comprising a longitudinally travellingbulkhead supported from said body, a longitudinally travelling load barat one end of the body and supported therefrom for reciprocation,endless chain means drivingly connected to the load bar for drivinglyreciprocating the load bar in both directions a distance at least equalto the length of a load unit to enable load units to be positioned onthe conveyor means inwardly of the load bar for movement into the loadbody during a loading operation, drive means fixedly connected with thebulkhead for moving the bulkhead longitudinally toward the loading barwhen actuated for unloading load units, a single power means for drivingthe bulkhead and load bar, and manually operated means selectivelyconnecting the drive means for the load bar and bulkhead to the powermeans for operating the assembly in a loading mode or unloading mode,said manually operated means preventing simultaneous actuation of theload bar and bulkhead.
 2. The structure as defined in claim 1 whereinsaid loading bar includes a pair of support members extendinglongitudinally of the body, a pair of rigid guide rails engaging andsupporting said support members for supporting and guiding the load barduring longitudinal reciprocation.
 3. The structure as defined in claim1 wherein said bulkhead includes a vertically upstanding andtransversely extending member, supporting roller means carried by saidbulkhead for engaging the body and rollingly supporting the bulkhead inrelation thereto.
 4. The structure as defined in claim 1 wherein saidmeans driving the bulkhead includes an elongated chain supported fromthe body and including an elongated upper run disposed under thebulkhead and being fixedly attached thereto whereby movement of thechain in either direction will cause longitudinal movement of thebulkhead.
 5. The structure as defined in claim 1 wherein said means forselectively controlling driving actuation of the bulkhead and load barincluding a manually shiftable clutch mechanism for selective engagementwith the drive connection with the load bar and bulkhead, reversiblemotor means drivingly connected with the clutch for selectively drivingthe load bar and bulkhead.
 6. The structure as defined in claim 1wherein said load body is in the form of a van trailer having twolongitudinal compartments therein separated by a partition with eachcompartment having a conveyor means and a loading and unloading assemblytherein, said load units being in the form of palletized beveragecontainers to enable loading and unloading of the body from one endthereof thereby eliminating the necessity of obtaining access throughoutthe opposed side walls of the body.
 7. The structure as defined in claim6 wherein said cOnveyor means is in the form of a plurality oflongitudinal rows of rotatably rollers supporting the load units attransversely spaced points, said rollers being freely rotatable forenabling movement of the load units thereon when forces are exerted onthe load units.
 8. The structure as defined in claim 7 wherein saidloading bar includes a pair of support members extending longitudinallyof the body, a pair of rigid guide rails engaging and supporting saidsupport members for supporting and guiding the load bar duringlongitudinal reciprocation, said bulkhead including a verticallyupstanding and transversely extending member, supporting roller meanscarried by said bulkhead for engaging the body and rollingly supportingthe bulkhead in relation thereto, said means driving the bulkheadincluding an elongated chain supported from the body and including anelongated upper run disposed under the bulkhead and being fixedlyattached thereto whereby movement of the chain in either direction willcause longitudinal movement of the bulkhead, said means driving thebulkhead being rendered inoperative when the load bar is beingreciprocated.
 9. A load unit handling device in combination with a loadbody of a vehicle in which the body includes a low-friction, rollerequipped bed continuously supporting the load units, an elongated drivemember supported in close proximity to said bed and being movable alonga reversible, predetermined path along said bed, said path terminatingadjacent forward and rearward extremities of the bed, an unloadingmember connected to said elongated drive member for movementcontinuously therewith, a shorter drive member supported in closeproximity to said bed and being movable along a reversible,predetermined path along said bed, said path of the shorter drive memberterminating at one end at the rearward end of the bed rearwardly of thepath of the elongated drive member and at the other end a distanceforwardly of the rearward end of the bed substantially equal to thefore-to-aft dimension of a load unit, a loading unit disposed above thebed and connected with said shorter drive member for movementcontinuously therewith, a single reversible power means supportedadjacent the bed, and means connecting the power means to said drivemembers, said connecting means including a shiftable means to actuateonly one of said drive members at a time for loading and unloading aplurality of load units from the rearward end of the bed.